Problem: $-\dfrac{2}{6} + \dfrac{8}{10} = {?}$
Explanation: $ = - {\dfrac{2 \times 5}{6 \times 5}} + {\dfrac{8 \times 3}{10 \times 3}} $ $ = - {\dfrac{10}{30}} + {\dfrac{24}{30}} $ $ = - \dfrac{{10} + {24}}{30} $ $ = \dfrac{14}{30}$